Author: Dan Newman
Date: 17:45:42 07/31/00
Go up one level in this thread
On July 31, 2000 at 20:38:16, Dan Newman wrote:
>On July 31, 2000 at 13:17:20, Larry Griffiths wrote:
>
>>I am currently using a bubble sort to sort my captures list.
>>
>>I plan to change it to a selection sort.
>>
>>Do any of you use another type of sort like quicksort to sort your lists or do
>>you have any preferences?
>>
>>Larry :)
>
>The capture list is almost always very short (0-6 items) so doing this with
>a bubble sort isn't bad at all. Crafty used a bubble sort for this until
>recently. (Bob switched over to straight insertion after a long debate
>here on the best way to sort captures. But, according to Bob, the straight
>insertion is no faster.) I haven't tried selection on the captures though,
>and I guess it could be faster. But I suspect it would only make a very
>small (nearly unmeasureable) difference in node rate...
>
>Here's what straight insertion (which I got from Numerical Recipes) looks
>like:
>
>
> for( j = 1; j < N; j++ ) {
> temp = arr[j];
> i = j-1;
> while( i >= 0 && arr[i] < temp ) {
> arr[i+1] = arr[i];
> i--;
> }
> arr[i+1] = temp;
> }
>
>You can look in Crafty's quiesce.c for what it looks like in a chess
>program with both move and score vectors.
>
>-Dan.
PS. I once used the built-in C library qsort() to sort my moves at the
root. When I compiled my program with three different compilers
(Watcom, MSVC, Gnu) I got three different node count results on fixed
depth searches. It took me a long while to figure out why :).
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